Endoscope system and endoscope processor

ABSTRACT

An endoscope system is provided with: a processor; a light source; and an image pickup device. The processor performs control for causing reflected light images corresponding to a predetermined period before start of the fluorescence occurrence period during the fluorescence non-occurrence period, among the reflected light images, to be recorded to the first storage medium; and, furthermore, performs control for causing the reflected light images to be recorded to the first storage medium during an after-end-of-fluorescence-occurrence period corresponding to a predetermined period with an end of the fluorescence occurrence period as a start point, and performs control for causing the reflected light images not to be recorded to the first storage medium during the fluorescence non-occurrence period after an end of the after-end-of-fluorescence-occurrence period.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of PCT/JP2018/039677filed on Oct. 25, 2018 and claims benefit of Japanese Application No.2017-242985 filed in Japan on Dec. 19, 2017, the entire contents ofwhich are incorporated herein by this reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an endoscope system and an endoscopeprocessor, and in particular to an endoscope system used for observationof an inside of a subject and an endoscope processor.

2. Description of the Related Art

In endoscopic observation in a medical field, white light observationhas been conventionally performed, which is such an observation methodthat, by radiating red light, green light and blue light by timedivision or simultaneously, for example, to an object such as livingtissue existing inside a subject, white light images provided withvisibility that is substantially the same as visibility in the case ofseeing the subject with naked eyes are acquired.

Further, in endoscopic observation in the medical field, special lightobservation has been conventionally performed, which is such anobservation method that, by radiating special light, for example, toliving tissue existing inside a subject, the special light being lightto which bandwidth restrictions are applied according to characteristicsof a predetermined target object included in the living tissue, speciallight images in which visibility of the predetermined target object isimproved in comparison with the white light observation are acquired.

As the special light observation described above, fluorescenceobservation has been conventionally known, which is such an observationmethod that, by radiating, for example, to living tissue existing insidea subject to whom an fluorescent agent has been administered in advance,excitation light including an excitation wavelength of the fluorescentagent and picking up images of fluorescence emitted from the livingtissue in response to the radiation of the excitation light,fluorescence images with improved visibility of a lesion or the like inthe living tissue are acquired.

More specifically, for example, Japanese Patent Application Laid-OpenPublication No. 2001-299676 discloses such a configuration that, byradiating excitation light with a wavelength of 790 nm to a living-bodyobservation part into which ICG (indocyanine green) has been injected inadvance, and picking up images of fluorescence emitted from theliving-body observation part in response to the radiation of theexcitation light, fluorescence images with improved visibility of asentinel lymph node included in the living-body observation part areacquired.

SUMMARY OF THE INVENTION

An endoscope system of an aspect of the present invention is providedwith: a processor; a light source configured to be capable of emittingexcitation light for causing a fluorescent agent administered to asubject to be excited and illumination light for illuminating an insideof the subject; and an image pickup device configured to pick up imagesof each of fluorescence that occurs in response to radiation of theexcitation light to an object existing inside the subject to whom thefluorescent agent has been administered, and reflected light that occursin response to radiation of the illumination light to the object;wherein the processor generates and sequentially outputs reflected lightimages which are images corresponding to the reflected light picked upby the image pickup device; generates and sequentially outputsfluorescence images which are images corresponding to the fluorescencelight picked up by the image pickup device; records each of thesequentially outputted reflected light images and the sequentiallyoutputted fluorescence images to a first storage medium; performscontrol for causing the reflected light images and the fluorescenceimages to be recorded to the first storage medium in a fluorescenceoccurrence period, which is a period during which the fluorescenceoccurs, performs control for causing the fluorescence images not to berecorded to the first storage medium during a fluorescencenon-occurrence period, which is a period during which the fluorescencedoes not occur, and performs control for causing reflected light imagescorresponding to a predetermined period before start of the fluorescenceoccurrence period during the fluorescence non-occurrence period, amongthe reflected light images, to be recorded to the first storage medium;and furthermore, performs control for causing the reflected light imagesto be recorded to the first storage medium during anafter-end-of-fluorescence-occurrence period corresponding to apredetermined period with an end of the fluorescence occurrence periodas a start point, and performs control for causing the reflected lightimages not to be recorded to the first storage medium during thefluorescence non-occurrence period after an end of theafter-end-of-fluorescence-occurrence period.

An endoscope system of another aspect of the present invention isprovided with: a processor; a light source configured to be capable ofemitting excitation light for causing a fluorescent agent administeredto a subject to be excited and illumination light for illuminating aninside of the subject; and an image pickup device configured to pick upimages of each of fluorescence that occurs in response to radiation ofthe excitation light to an object existing inside the subject to whomthe fluorescent agent has been administered, and reflected light thatoccurs in response to radiation of the illumination light to the object;wherein the processor generates and sequentially outputs reflected lightimages which are images corresponding to the reflected light picked upby the image pickup device; generates and sequentially outputsfluorescence images which are images corresponding to the fluorescencelight picked up by the image pickup device; records each of thesequentially outputted reflected light images and the sequentiallyoutputted fluorescence images to a first storage medium; performscontrol for causing the reflected light images and the fluorescenceimages to be recorded to the first storage medium in a fluorescenceoccurrence period, which is a period during which the fluorescenceoccurs, performs control for causing the fluorescence images not to berecorded to the first storage medium in a fluorescence non-occurrenceperiod, which is a period during which the fluorescence does not occur,and performs control for causing the reflected light imagescorresponding to a predetermined period before start of the fluorescenceoccurrence period during the fluorescence non-occurrence period, amongthe reflected light images, to be recorded to the first storage medium;furthermore, holds a predetermined number of the sequentially outputtedreflected light images in a second storage medium; and performs controlfor causing the predetermined number of the reflected light images to beheld in the second storage medium during abefore-start-of-fluorescence-occurrence period corresponding to a periodbefore start of occurrence of the fluorescence during the fluorescencenon-occurrence period, and performs control for causing output of thereflected light images to the second storage medium to be stopped,control for causing the predetermined number of the reflected lightimages held in the second storage medium to be outputted to the firststorage medium and control for causing recording of the sequentiallyoutputted reflected light images to the first storage medium to bestarted, at the start of the fluorescence occurrence period.

An endoscope processor of an aspect of the present invention includes aprocessor configured to process a signal about fluorescence generated bycausing a fluorescent agent administered to a subject to be excited anda signal about reflected light that occurs in response to illuminationto an inside of the subject; wherein the processor generates reflectedlight images from the signal about the reflected light and sequentiallyoutputs the reflected light images; generates fluorescence images fromthe signal about the fluorescence and sequentially outputs thefluorescence light images; performs control for causing the reflectedlight images and the fluorescence images to be recorded to an externalrecording apparatus in a fluorescence occurrence period, which is aperiod during which the fluorescence occurs, performs control forcausing the fluorescence images not to be recorded to the externalrecording apparatus in a fluorescence non-occurrence period, which is aperiod during which the fluorescence does not occur, and performscontrol for causing reflected light images corresponding to apredetermined period before start of the fluorescence occurrence periodduring the fluorescence non-occurrence period, among the reflected lightimages, to be recorded to the external recording apparatus; andfurthermore, performs control for causing the reflected light images tobe recorded to the external recording apparatus during anafter-end-of-fluorescence-occurrence period corresponding to apredetermined period with an end of the fluorescence occurrence periodas a start point, and performs control for causing the reflected lightimages not to be recorded to the external recording apparatus during thefluorescence non-occurrence period after an end of theafter-end-of-fluorescence-occurrence period.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a configuration of a main part of anendoscope system according to an embodiment;

FIG. 2 is a block diagram for illustrating an example of a specificconfiguration of a video recording apparatus in the endoscope systemaccording to the embodiment;

FIG. 3 is a diagram showing an example of a display aspect of anobservation image displayed in a fluorescence observation mode;

FIG. 4 is a diagram for illustrating an example of a recording state ofimages in the video recording apparatus according to the embodiment;

FIG. 5 is a diagram for illustrating an example of the recording stateof images in the video recording apparatus according to the embodiment;

FIG. 6 is a diagram for illustrating an example of the recording stateof images in the video recording apparatus according to the embodiment;

FIG. 7 is a diagram for illustrating an example of additionalinformation recorded to the video recording apparatus according to theembodiment;

FIG. 8 is a diagram for illustrating an example of the additionalinformation recorded to the video recording apparatus according to theembodiment; and

FIG. 9 is a diagram for illustrating an example of the additionalinformation recorded to the video recording apparatus according to theembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

An embodiment of the present invention will be described below withreference to drawings.

FIGS. 1 to 9 relate to the embodiment of the present invention.

For example, as shown in FIG. 1, an endoscope system 1 has an endoscope2 which is to be inserted into an inside of a subject and is configuredto pick up images of an object such as living tissue existing inside thesubject and output an image pickup signal, a light source apparatus 3configured to supply light to be radiated to the object, to theendoscope 2, a processor 4 configured to, by performing variousprocessing for the image pickup signal outputted from the endoscope 2,generate and output an observation image; a display apparatus 5configured to display the observation image outputted from the processor4 on a screen; and a video recording apparatus 6 configured tovideo-record the image outputted from the processor 4. FIG. 1 is adiagram showing a configuration of a main part of an endoscope systemaccording to the embodiment.

For example, as shown in FIG. 1, the endoscope 2 is configured having aninsertion portion 21 formed in an elongated shape insertable into aninside of a subject and an operation portion 22 provided on a proximalend side of the insertion portion 21. The endoscope 2 is provided with aconfiguration of being attachable to and detachable from the lightsource apparatus 3 via a light guide cable 27. Further, the endoscope 2is provided with a configuration of being attachable to and detachablefrom the processor 4 via a signal cable 28 extended from the operationportion 22.

A light guide 11 for transmitting light supplied from the light sourceapparatus 3 is inserted inside the insertion portion 21 and the lightguide cable 27.

As shown in FIG. 1, an emission end portion of the light guide 11 isarranged near an illumination lens 12 on a distal end portion of theinsertion portion 21. As shown in FIG. 1, an incident end portion of thelight guide 11 is arranged near a condensing lens 32 in the light sourceapparatus 3 connected to the endoscope 2 via the light guide cable 27.

On the distal end portion of the insertion portion 21, the illuminationlens 12 for emitting light transmitted by the light guide 11 to anobject and an image pickup portion 13 for picking up images of returnlight from the object are provided.

The image pickup portion 13 is configured to pick up images of each offluorescence FLA (to be described later) that occurs in response toradiation of excitation light EXA (to be described later) to an objectexisting inside a subject to whom fluorescent agent has beenadministered, and reflected light that occurs in response to radiationof white light WLA (to be described later) to the object. The imagepickup portion 13 has an objective lens 13 a configured to receivereturn light from the object, an image pickup device 13 b configured topick up images of the return light, and an excitation light cut filter13 c arranged on an optical path from the objective lens 13 a to theimage pickup device 13 b.

The image pickup device 13 b is provided, for example, with a color CMOSimage sensor, and is configured to perform an image pickup operationcorresponding to an image pickup device driving signal outputted fromthe processor 4. Further, the image pickup device 13 b is configured topick up images of light transmitted through the excitation light cutfilter 13 c to generate an image pickup signal and output the generatedimage pickup signal to the processor 4.

The excitation light cut filter 13 c is formed being provided with suchan optical characteristic that cuts off, for example, the samewavelength band as the excitation light EXA among respective wavelengthbands included in light emitted through the objective lens 13 a, andcauses wavelength bands different from a wavelength band of theexcitation light EXA to be transmitted. In other words, the excitationlight cut filter 13 c is formed being provided with such an opticalcharacteristic that causes the fluorescence FLA and the white light WLAemitted from a fluorescent agent in response to radiation of theexcitation light EXA to be transmitted.

The operation portion 22 is provided on the proximal end side of theinsertion portion 21 and is formed being provided with a shape that canbe grasped by a user such as a surgeon. Further, the operation portion22 is provided, for example, with a scope switch (not shown) which isone or more switches capable of giving various instructionscorresponding to operations by the user to the processor 4.

For example, as shown in FIG. 1, the light source apparatus 3 isconfigured having a light emitting portion 31, the condensing lens 32and a light source driving portion 33.

The light emitting portion 31 is configured having a white light source51, an excitation light source 52 and a dichroic mirror 53.

The white light source 51 is configured being provided, for example,with any of a xenon lamp, a white light LED, and an RGB three-color LED.The white light source 51 is configured to generate, for example, thewhite light WLA, which is light including respective wavelength bands ofa red region, a green region and a blue region, in response to a lightsource driving signal outputted from the light source driving portion33. Note that, in the present embodiment, the light source apparatus 3may be provided, for example, with a broadband light source configuredbeing provided with a lamp that emits broadband light, which is lightprovided with a wavelength band at least from the blue region to anear-infrared region, and an optical filter provided with such anoptical characteristic that causes the same wavelength band as the whitelight WLA, among respective wavelength bands included in the broadbandlight, to be transmitted and cuts out other wavelength bands, instead ofthe white light source 51.

The excitation light source 52 is configured, for example, beingprovided with an LD (a laser diode). Further, the excitation lightsource 52 is configured to generate, for example, the excitation lightEXA, which is narrowband light including an excitation wavelength of apredetermined fluorescent agent administered to a subject, in responseto a light source driving signal outputted from the light source drivingportion 33. Note that, hereinafter, description will be made on anassumption that the fluorescent agent administered to a subject is ICG(indocyanine green), that the excitation light EXA is narrowbandnear-infrared light including an excitation wavelength of the ICG (forexample, a wavelength of 808 nm or a near 808 nm), and that thefluorescence FLA, which is near-infrared light belonging to a wavelengthband on a longer wavelength side than the excitation light EXA, isemitted from the ICG, unless otherwise stated.

The dichroic mirror 53 is configured being provided, for example, withsuch an optical characteristic that causes the white light WLA emittedfrom the white light source 51 to be transmitted to emit the white lightWLA to the condensing lens 32 side, and reflects the excitation lightEXA emitted from the excitation light source 52 to emit the excitationlight EXA to the condensing lens 32 side.

In other words, the light emitting portion 31 is configured to becapable of generating the white light WLA by causing the white lightsource 51 to emit light in response to a driving signal outputted fromthe light source driving portion 33. Further, the light emitting portion31 is configured to be capable of generating the excitation light EXA bycausing the excitation light source 52 to emit light in response to adriving signal outputted from the light source driving portion 33.Further, the light emitting portion 31 is configured to be capable ofemitting the white light WLA and the excitation light EXA to thecondensing lens 32.

The condensing lens 32 is configured to condense light emitted from thelight emitting portion 31 and emit the light to the incident end portionof the light guide 11.

The light source driving portion 33 is configured to generate a lightsource driving signal for driving the white light source 51 and theexcitation light source 52 to output the light source driving signal tothe light emitting portion 31, based on a control signal outputted fromthe processor 4.

In other words, the light source apparatus 3 is configured to be capableof emitting the excitation light EXA for causing a fluorescent agentadministered to a subject to be excited and the white light WLA which isillumination light for illuminating an inside of the subject.

For example, as shown in FIG. 1, the processor 4 is configured having animage pickup device driving portion 41, a selector 42, a white lightimage generating portion 43, a fluorescence image generating portion 44,a superposed image generating portion 45, an image analyzing portion 46,an observation image generating portion 47, an input I/F (interface) 48and a controlling portion 49. Note that, in the present embodiment, eachof portions other than the input I/F 48 in the processor 4 may beconfigured as an individual electronic circuit or may be configured as acircuit block in an integrated circuit such as an FPGA (fieldprogrammable gate array). Further, in the present embodiment, forexample, the processor 4 may be configured being provided with one ormore CPUs. Further, by appropriately modifying a configuration accordingto the present embodiment, for example, a program for causing a functionof each of the portions other than the input I/F 48 in the processor 4to be executed may be read from a storage medium such as a memory, andan operation according to the read program may be performed on acomputer.

The image pickup device driving portion 41 is configured to generate andoutput an image pickup device driving signal for causing the imagepickup device 13 b to be driven, based on a control signal outputtedfrom the controlling portion 49.

The selector 42 is configured to perform an operation for setting anoutput destination of an image pickup signal outputted from theendoscope 2 to either the white light image generating portion 43 or thefluorescence image generating portion 44, based on a control signaloutputted from the controlling portion 49.

The white light image generating portion 43 is configured to generatewhite light images WIA based on an image pickup signal outputted via theselector 42 and sequentially output the generated white light images WIAto each of the superposed image generating portion 45, the observationimage generating portion 47 and the video recording apparatus 6 one byone. In other words, the white light image generating portion 43 isprovided with a function as a reflected light image generating portionand is configured to generate the white light images WIA which areimages corresponding to reflected light of the white light WLA whichhave been picked up by the image pickup portion 13.

The fluorescence image generating portion 44 is configured to generatefluorescence images FIA based on an image pickup signal outputted viathe selector 42 and sequentially output the generated fluorescenceimages FIA to each of the superposed image generating portion 45, theimage analyzing portion 46, the observation image generating portion 47and the video recording apparatus 6 one by one. In other words, thefluorescence image generating portion 44 is configured to generate thefluorescence images FIA which are images corresponding to thefluorescence FLA which have been picked up by the image pickup portion13.

The superposed image generating portion 45 is configured to generatesuperposed images SIA by performing a process for superposing the whitelight images WIA outputted from the white light image generating portion43 and the fluorescence images FIA outputted from the fluorescence imagegenerating portion 44 and sequentially output the generated superposedimages SIA to each of the observation image generating portion 47 andthe video recording apparatus 6 one by one.

More specifically, the superposed image generating portion 45 performssuch a process that, by superposing a pixel value of a pixel WP at onepixel position on a white light image WIA outputted from the white lightimage generating portion 43 and a pixel value of a pixel FP at the onepixel position on a fluorescence image FIA outputted from thefluorescence image generating portion 44, a pixel value of a pixel SP atthe one pixel position on a superposed image SIA for the whole imagearea, for example, using Equation (1) below.

Note that, in Equation (1) below, it is assumed that Ri indicates abrightness value of a red component of the pixel WP, Gi indicates abrightness value of a green component of the pixel WP, Bi indicates abrightness value of a blue component of the pixel WP, Fi indicates abrightness value of (a fluorescence component) of the pixel FP, Roindicates a brightness value of a red component of the pixel SP, Goindicates a brightness value of a green component of the pixel SP, andBo indicates a brightness value of a blue component of the pixel SP.Further, a, (3 and yin Equation (1) below indicate weight coefficientsfor specifying a color tone at a position where the fluorescence FLAincluded in the superposed image SIA occurs and may be, for example,fixed values set in advance by the superposed image generating portion45 or variable values set according to a control signal from thecontrolling portion 49.

$\begin{matrix}{\begin{pmatrix}{Ro} \\{Go} \\{Bo}\end{pmatrix} = {\begin{pmatrix}1 & 0 & 0 & \alpha \\0 & 1 & 0 & \beta \\0 & 0 & 1 & \gamma\end{pmatrix}\begin{pmatrix}{Ri} \\{Gi} \\{Bi} \\{Fi}\end{pmatrix}}} & (1)\end{matrix}$

The image analyzing portion 46 is configured to perform a process foranalyzing whether a fluorescence occurrence area is included in thefluorescence image FIA based on a feature value related to brightness ofthe fluorescence image FIA outputted from the fluorescence imagegenerating portion 44 and output analysis result information showing ananalysis result obtained by the process to the video recording apparatus6.

More specifically, the image analyzing portion 46 performs, for example,a process for calculating a feature value FAV related to brightness of afluorescence image FIA outputted from the fluorescence image generatingportion 44 and judging whether or not the calculated feature value FAVis equal to or above a predetermined threshold THV. Then, for example,when detecting that the feature value FAV is equal to or above thethreshold THV, the image analyzing portion 46 acquires an analysisresult that a fluorescence occurrence area is included in thefluorescence image FIA outputted from the fluorescence image generatingportion 44, and outputs analysis result information showing the acquiredanalysis result to the video recording apparatus 6. For example, whendetecting that the feature value FAV is below the threshold THV, theimage analyzing portion 46 acquires an analysis result that anfluorescence occurrence area is not included in the fluorescence imageFIA outputted from the fluorescence image generating portion 44, andoutputs analysis result information showing the acquired analysis resultto the video recording apparatus 6.

Note that the image analyzing portion 46 of the present embodiment maybe configured to perform the process, for example, using an arbitraryfeature value like an average value of brightness values of respectivepixels included in the fluorescence image FIA outputted from thefluorescence image generating portion 44 as the feature value FAV as faras it is possible to identify whether an fluorescence occurrence area isincluded in the fluorescence image FIA or not. Further, in the presentembodiment, the image analyzing portion 46 may be provided in the videorecording apparatus 6.

The observation image generating portion 47 is configured to generate anobservation image based on a white light image WIA outputted from thewhite light image generating portion 43, a fluorescence image FIAoutputted from the fluorescence image generating portion 44, asuperposed image SIA outputted from the superposed image generatingportion 45 and a control signal outputted from the controlling portion49 and output the generated observation image to the display apparatus5.

The input I/F (interface) 48 is configured being provided one or moreswitches and/or buttons capable of giving an instruction correspondingto an operation by the user. More specifically, the input I/F 48 isconfigured being provided, for example, with an observation modeswitching switch (not shown) capable of giving an instruction forsetting (switching) an observation mode of the endoscope system 1 toeither a white light observation mode or a fluorescence observationmode. Further, the input I/F 48 is configured being provided, forexample, with a display image switching switch (not shown) capable ofgiving an instruction for setting (switching) an image caused to bedisplayed on the display apparatus 5 in the fluorescence observationmode to either the white light image WIA or the superposed image SIA.

The controlling portion 49 is configured to be capable of generating acontrol signal for causing an operation corresponding to an instructionfrom the input I/F 48 to be performed, and output the control signal toeach of the light source driving portion 33 and the observation imagegenerating portion 47. Further, the controlling portion 49 is configuredbeing provided with a storage medium (not shown) such as a memory inwhich control information to be used at the time of controlling eachportion of the endoscope system 1 is stored.

The controlling portion 49 is configured to generate a control signalrelated to an image pickup operation to be performed by the image pickupdevice 13 b, according to an observation mode set by the observationmode switching switch of the input I/F 48, and output the control signalto the image pickup device driving portion 41. Further, the controllingportion 49 is configured to generate a control signal for setting anoutput destination of an image pickup signal to be inputted to theprocessor 4, according to an observation mode set by the observationmode switching switch of the input I/F 48, and output the control signalto the selector 42. Further, the controlling portion 49 is configured togenerate observation mode information including information by which acurrently set observation mode of the endoscope system 1 can beidentified, based on an instruction from the observation mode switchingswitch of the input I/F 48 and output the generated observation modeinformation to the video recording apparatus 6.

The display apparatus 5 is provided, for example, with an LCD (liquidcrystal display) and the like and is configured to be capable ofdisplaying an observation image and the like outputted from theprocessor 4.

The video recording apparatus 6 is configured to perform an operationfor recording, among respective images outputted from the white lightimage generating portion 43, the fluorescence image generating portion44 and the superposed image generating portion 45, an imagecorresponding to an analysis result outputted from the image analyzingportion 46 and observation mode information outputted from thecontrolling portion 49. For example, as shown in FIG. 2, the videorecording apparatus 6 is configured having an image inputting portion81, an image holding portion 82, an image recording portion 83, an inputI/F 84, a video recording controlling portion 85 and a video recordingmanaging portion 86. Note that, in the present embodiment, each ofportions other than the input I/F 84 in the video recording apparatus 6may be configured as an individual electronic circuit or may beconfigured as a circuit block in an integrated circuit such as an FPGA(field programmable gate array). Further, in the present embodiment, forexample, the video recording apparatus 6 may be configured beingprovided with one or more CPUs. Further, by appropriately modifying aconfiguration according to the present embodiment, for example, aprogram for causing a function of each of the portions other than theinput I/F 84 in the video recording apparatus 6 to be executed may beread from a storage medium such as a memory, and an operation accordingto the read program may be performed on a computer. FIG. 2 is a blockdiagram for illustrating an example of a specific configuration of avideo recording apparatus in the endoscope system according to theembodiment.

The image inputting portion 81 is configured so that each of white lightimages WIA sequentially outputted from the white light image generatingportion 43, fluorescence images FIA sequentially outputted from thefluorescence image generating portion 44 and superposed images SIAsequentially outputted from the superposed image generating portion 45is inputted. Further, the image inputting portion 81 is configured toperform an operation for outputting at least one image among the whitelight images WIA, the fluorescence images FIA and the superposed imagesSIA to an output destination corresponding to control of the videorecording managing portion 86.

The image holding portion 82 constituting a second storage medium isconfigured being provided, for example, with a volatile storage mediumlike a video memory. Further, the image holding portion 82 is configuredto be capable of holding a predetermined number of images sequentiallyoutputted via the image inputting portion 81. In other words, the imageholding portion 82 is configured to be capable of holding apredetermined number of white light images WIA sequentially outputtedfrom the white light image generating portion 43 via the image inputtingportion 81. Further, the image holding portion 82 is configured toperform an operation for replacing the oldest image among the currentlyheld predetermined number of images with the newest image outputted viathe image inputting portion 81. Further, the image holding portion 82 isconfigured to perform an operation for outputting the currently heldpredetermined number of images to the image recording portion 83according to control of the video recording managing portion 86.

The image recording portion 83 constituting a first storage medium isconfigured being provided, for example, with a nonvolatile storagemedium like a hard disk or the like. The image recording portion 83 isconfigured to be capable of recording each of the white light images WIAsequentially outputted from the white light image generating portion 43via the image inputting portion 81, the fluorescence images FIAsequentially outputted from the fluorescence image generating portion 44via the image inputting portion 81 and the superposed images SIAsequentially outputted from the superposed image generating portion 45via the image inputting portion 81. Further, the image recording portion83 is configured to perform an operation for recording at least oneimage among the white light images WIA, the fluorescence images FIA andthe superposed images SIA according to control of the video recordingmanaging portion 86. Further, the image recording portion 83 isconfigured to perform an operation for generating and recordingadditional information about currently recorded images, according tocontrol of the video recording managing portion 86.

The input I/F 84 is configured being provided one or more switchesand/or buttons capable of giving an instruction corresponding to anoperation by the user. More specifically, the input I/F 84 is configuredbeing provided, for example, with a recorded image setting switch (notshown) capable of giving an instruction for setting at least one imageamong the white light images WIA, the fluorescence images FIA and thesuperposed images SIA, as an image caused to be recorded to the videorecording apparatus 6. Further, the input I/F 84 is configured beingprovided, for example, with a video recording mode setting switch (notshown) capable of giving an instruction for setting a video recordingmode in the case of causing white light images WIA or superposed imagesSIA to be recorded to the video recording apparatus 6, to one videorecording mode among a plurality of video recording modes.

The video recording controlling portion 85 is configured to generate andoutput video recording control information, which is information to beused for control by the video recording managing portion 86, based onanalysis result information outputted from the image analyzing portion46, observation mode information outputted from the controlling portion49 and an instruction from the input I/F 84. Note that a specificexample of the operation performed by the video recording controllingportion 85 will be described later.

The video recording managing portion 86 is configured to control anoperation of each of the image inputting portion 81, the image holdingportion 82 and the image recording portion 83 based on the videorecording control information outputted from the video recordingcontrolling portion 85. Note that a specific example of the controlperformed by the video recording managing portion 86 will be describedlater. Note that, in the present embodiment, for example, the videorecording managing portion 86 may be provided in the processor 4.

Next, an operation and the like of the endoscope system 1 of the presentembodiment will be described. Note that, hereinafter, description willbe advanced on an assumption that, before fluorescence observation of adesired object existing inside a subject is performed, ICG which is afluorescent agent is administered to the subject or the desired objectin advance.

For example, by operating the observation mode switching switch of theinput I/F 48 after connecting each portion of the endoscope system 1 andturning on power, the user such as a surgeon gives an instruction forsetting the observation mode of the endoscope system 1 to the whitelight observation mode.

When detecting that the instruction for setting the observation mode ofthe endoscope system 1 to the white light observation mode has beengiven, the controlling portion 49 outputs a control signal for causingthe white light WLA to be generated, to the light source driving portion33.

When detecting that the instruction for setting the observation mode ofthe endoscope system 1 to the white light observation mode has beengiven, the controlling portion 49 outputs a control signal for causingwhite light images WIA to be displayed as observation images, to theobservation image generating portion 47.

When detecting that the instruction for setting the observation mode ofthe endoscope system 1 to the white light observation mode has beengiven, the controlling portion 49 generates a control signal for causinga predetermined image pickup operation to be performed and outputs thecontrol signal to the image pickup device driving portion 41; and thecontrolling portion 49 also generates a control signal for setting anoutput destination of an image pickup signal to be inputted to theprocessor 4, to the white light image generating portion 43, and outputsthe control signal to the selector 42.

According to the control signal outputted from the controlling portion49, the light source driving portion 33 generates a light source drivingsignal for causing the white light source 51 to be turned on and causingthe excitation light source 52 to be turned off and outputs the lightsource driving signal to the light emitting portion 31, in the whitelight observation mode.

According to the operation as described above, in the white lightobservation mode, the white light WLA emitted from the white lightsource 51 is supplied to the endoscope 2; images of reflected light ofthe white light WLA, which is return light from an object illuminated bythe white light WLA, are picked up by the image pickup portion 13; andwhite light images WIA corresponding to an image pickup signal outputtedfrom the image pickup portion 13 are generated by the white light imagegenerating portion 43 and displayed on the display apparatus 5 asobservation images.

For example, by operating the recorded image setting switch of the inputOF 84 in the state in which the observation mode of the endoscope system1 is set to the white light observation mode, the user gives aninstruction for causing the white light images WIA to be recorded to thevideo recording apparatus 6.

The controlling portion 49 generates observation mode informationshowing that the currently set observation mode of the endoscope system1 is the white light observation mode, based on the instruction from theobservation mode switching switch of the input I/F 48, and outputs thegenerated observation mode information to the video recording apparatus6.

The video recording controlling portion 85 generates video recordingcontrol information for causing the white light images WIA to berecorded to the image recording portion 83, based on the observationmode information outputted from the controlling portion 49 and theinstruction from the recorded image setting switch of the input I/F 84,and outputs the video recording control information to the videorecording managing portion 86.

The video recording managing portion 86 performs control for setting anoutput destination of the white light images WIA to the image recordingportion 83, to the image inputting portion 81, based on the videorecording control information outputted from the video recordingcontrolling portion 85.

According to the operation as described above, in the white lightobservation mode, the white light images WIA sequentially outputted fromthe white light image generating portion 43 are recorded to the imagerecording portion 83 via the image inputting portion 81.

In the state in which the observation mode of the endoscope system 1 isset to the white light observation mode, the user inserts the insertionportion 21 into an inside of an examinee while confirming theobservation images displayed on the display apparatus 5, and arrangesthe distal end portion of the insertion portion 21 at such a positionthat a desired object (living tissue) inside the examinee (including,for example, an area to be a blood flow evaluation target) is includedin an observation field of view of the objective lens 13 a. After that,by operating the observation mode switching switch of the input I/F 48,the user gives an instruction for setting the observation mode of theendoscope system 1 to the fluorescence observation mode. Further, byoperating the display image switching switch of the input I/F 48, theuser gives an instruction for causing either white light images WIA orsuperposed images SIA to be displayed on the display apparatus 5 as mainimages MIA.

When detecting that the instruction for setting the observation mode ofthe endoscope system 1 to the fluorescence observation mode has beengiven, the controlling portion 49 generates a control signal for causingobservation images including main images MIA and fluorescence images FIAto be generated and outputs the control signal to the observation imagegenerating portion 47, according to an instruction from the displayimage switching switch of the input I/F 48.

When detecting that the instruction for setting the observation mode ofthe endoscope system 1 to the fluorescence observation mode has beengiven, the controlling portion 49 generates a control signal for causinga timing of occurrence of the white light WLA and the excitation lightEXA by the light emitting portion 31, an image pickup operation by theimage pickup device 13 b, and an output destination of an image pickupsignal to be inputted to the processor 4 to be synchronized, and outputsthe control signal to each of the light source driving portion 33, theimage pickup device driving portion 41 and the selector 42.

More specifically, for example, the controlling portion 49 generates acontrol signal for causing the image pickup device 13 b to perform arolling-shutter-method image pickup operation and outputs the controlsignal to the image pickup device driving portion 41. Further, forexample, the controlling portion 49 generates a control signal forcausing a predetermined amount of white light WLA and the predeterminedamount of excitation light EXA to be generated alternately (by timedivision) for each blanking period, which is a period during whichreading is not performed on any line of the image pickup device 13 b inthe rolling shutter method image pickup operation, and outputs thecontrol signal to the light source driving portion 33. Further, forexample, the controlling portion 49 generates a control signal forsetting an output destination of an image pickup signal inputted to theprocessor 4 when the white light WLA occurs, to the white light imagegenerating portion 43, and setting an output destination of an imagepickup signal inputted to the processor 4 when the excitation light EXAoccurs, to the fluorescence image generating portion 44, and outputs thecontrol signal to the selector 42.

According to the control of the controlling portion 49 described above,for example, the white light WLA is radiated to the object during afirst blanking period of the image pickup device 13 b; images ofreflected light of the white light WLA, which is return light from theobject, are picked up by the image pickup portion 13; an image pickupsignal generated by the image pickup portion 13 are outputted to thewhite light image generating portion 43 via the selector 42; white lightimages WIA generated based on the image pickup signal are sequentiallyoutputted to each of the superposed image generating portion 45, theobservation image generating portion 47 and the video recordingapparatus 6 one by one.

Further, according to the control of the controlling portion 49described above, for example, the excitation light EXA is radiated tothe object during a second blanking period of the image pickup device 13b different from the first blanking period described above; images offluorescence FLA included in return light generated from the object arepicked up by the image pickup portion 13; an image pickup signalgenerated by the image pickup portion 13 is outputted to thefluorescence image generating portion 44 via the selector 42; andfluorescence images FIA generated based on the image pickup signal aresequentially outputted to each of the superposed image generatingportion 45, the image analyzing portion 46 and the video recordingapparatus 6 one by one.

For example, in a state in which the coefficients α, β and γ of Equation(1) above are set so that α=γ=0 and β=1 are satisfied, the superposedimage generating portion 45 generates superposed images SIA byperforming a process for superposing white light images WIA outputtedfrom the white light image generating portion 43 and fluorescence imagesFIA outputted from the fluorescence image generating portion 44 andoutputs the generated superposed images SIA to each of the observationimage generating portion 47 and the video recording apparatus 6. Inother words, according to such an operation of the superposed imagegenerating portion 45, such superposed images SIA that a position wherefluorescence FLA in the object which has been image-picked up by theendoscope 2 is shown in green are outputted to the observation imagegenerating portion 47 and the video recording apparatus 6.

According to the control signal outputted from the controlling portion49, the observation image generating portion 47 generates, for example,such P-in-P (picture-in-picture) images that, while main images MIA arecaused to be displayed in a display area DM, fluorescence images FIA arecaused to be displayed in a display area DS provided on a part in thedisplay area DM, as observation images DG, and outputs the generatedobservation images DG to the display apparatus 5, in the fluorescenceobservation mode. According to such an operation of the observationimage generating portion 47, for example, the observation images DGhaving a display aspect as shown in FIG. 3 are displayed on the displayapparatus 5. FIG. 3 is a diagram showing an example of a display aspectof an observation image displayed in the fluorescence observation mode.

For example, by operating the recorded image setting switch of the inputI/F 84 in the state in which the observation mode of the endoscopesystem 1 is set to the fluorescence observation mode, the user gives aninstruction for causing the white light images WIA and the fluorescenceimages FIA to be recorded to the video recording apparatus 6.

The controlling portion 49 generates observation mode informationshowing that the currently set observation mode of the endoscope system1 is the fluorescence observation mode, based on the instruction of theobservation mode switching switch of the input I/F 48 and outputs thegenerated observation mode information to the video recording apparatus6.

The image analyzing portion 46 performs a process for analyzing whethera fluorescence occurrence area is included in the fluorescence imagesFIA outputted from the fluorescence image generating portion 44 andoutputs analysis result information showing an analysis result obtainedby the process to the video recording apparatus 6.

Here, specific examples of operations performed in a plurality of videorecording modes that can be alternatively set by operating the videorecording mode setting switch of the input I/F 84 will be described.Note that it is assumed that the operations performed in each videorecording mode, which will be described below, are similarly appliedwhen superposed images SIA are recorded instead of white light imagesWIA in the fluorescence observation mode, unless otherwise stated.

For example, by operating the video recording mode setting switch of theinput I/F 84, the user gives an instruction for setting a videorecording mode RMA, a video recording mode in which white light imagesWIA sequentially outputted from the processor 4 in the fluorescenceobservation mode to be continuously recorded to the video recordingapparatus 6.

The video recording controlling portion 85 generates video recordingcontrol information for causing the white light images WIA to becontinuously recorded to the image recording portion 83, based on theobservation mode information outputted from the controlling portion 49and the instructions from the recorded image setting switch and thevideo recording mode setting switch of the input I/F 84, and outputs thevideo recording control information to the video recording managingportion 86.

The video recording controlling portion 85 generates video recordingcontrol information for, while causing fluorescence images FIA to berecorded to the image recording portion 83 during a fluorescenceoccurrence period PFP, which is a period during which an analysis resultthat a fluorescence occurrence area is included in the fluorescenceimages FIA is obtained, causing fluorescence images FIA not to berecorded to the image recording portion 83 during a fluorescencenon-occurrence period PFN, which is a period during which an analysisresult that an fluorescence occurrence area is not included in thefluorescence images FIA is obtained, and outputs the video recordingcontrol information to the video recording managing portion 86, based onthe analysis result information outputted from the image analyzingportion 46, the observation mode information outputted from thecontrolling portion 49 and the instruction from the recorded imagesetting switch of the input I/F 84.

The video recording managing portion 86 performs control for setting anoutput destination of the white light images WIA to the image recordingportion 83, to the image inputting portion 81 based on the videorecording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the white light images WIA to theimage recording portion 83 to be performed during the fluorescenceoccurrence period PFP and the fluorescence non-occurrence period PFN, tothe image inputting portion 81 based on the video recording controlinformation outputted from the video recording controlling portion 85.

The video recording managing portion 86 performs control for setting anoutput destination of the fluorescence images FIA to the image recordingportion 83, to the image inputting portion 81 based on the videorecording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the fluorescence images FIA tothe image recording portion 83 to be performed during the fluorescenceoccurrence period PFP, to the image inputting portion 81 based on thevideo recording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the fluorescence images FIA tothe image recording portion 83 to be stopped during the fluorescencenon-occurrence period PFN, to the image inputting portion 81 based onthe video recording control information outputted from the videorecording controlling portion 85.

According to the operation as described above, when the video recordingmode of the video recording apparatus 6 is set to the video recordingmode RMA, a movie WMA corresponding to a plurality of white light imagesWIA sequentially inputted to the image inputting portion 81 during abefore-start-of-fluorescence-occurrence period PFNA, which is a periodbefore a start of the fluorescence occurrence period PFP during thefluorescence non-occurrence period PFN, the fluorescence occurrenceperiod PFP, and an after-end-of-fluorescence-occurrence period PFNB,which is a period after an end of the fluorescence occurrence period PFPduring the fluorescence non-occurrence period, is recorded to the imagerecording portion 83, for example, as shown in FIG. 4. Further,according to the operation as described above, when the video recordingmode of the video recording apparatus 6 is set to the video recordingmode RMA, a movie FMA corresponding to a plurality of fluorescenceimages FIA sequentially inputted to the image inputting portion 81 inthe fluorescence occurrence period PFP is recorded to the imagerecording portion 83, for example, as shown in FIG. 4. FIG. 4 is adiagram for illustrating an example of a recording state of images inthe video recording apparatus according to the embodiment.

In other words, when the video recording mode of the video recordingapparatus 6 is set to the video recording mode RMA, the white lightimages WIA sequentially inputted to the video recording apparatus 6during the before-start-of-fluorescence-occurrence period PFNA, thefluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFNB are recorded as themovie WMA, and the fluorescence images FIA inputted to the videorecording apparatus 6 during the fluorescence occurrence period PFP arerecorded as the movie FMA. Further, when the video recording mode of thevideo recording apparatus 6 is set to the video recording mode RMA,control for causing the white light images WIA to be recorded to theimage recording portion 83 is performed by the video recording managingportion 86 during the before-start-of-fluorescence-occurrence periodPFNA, the fluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFNB. Further, when thevideo recording mode of the video recording apparatus 6 is set to thevideo recording mode RMA, control for causing the fluorescence imagesFIA not to be recorded to the image recording portion 83 is performed bythe video recording managing portion 86 during the fluorescencenon-occurrence period PFN. Further, when the video recording mode of thevideo recording apparatus 6 is set to the video recording mode RMA,control for causing the fluorescence images FIA to be recorded to theimage recording portion 83 is performed by the video recording managingportion 86 during the fluorescence occurrence period PFP.

Note that, in the present embodiment, for example, a timing when thevideo recording controlling portion 85 detects that the observation modeof the endoscope system 1 has been switched from the white lightobservation mode to the fluorescence observation mode may be a startpoint of the before-start-of-fluorescence-occurrence period PFNA.Further, in the present embodiment, for example, a timing when the videorecording controlling portion 85 detects that the observation mode ofthe endoscope system 1 has been switched from the fluorescenceobservation mode to the white light observation mode may be an end pointof the after-end-of-fluorescence-occurrence period PFNB.

For example, by operating the video recording mode setting switch of theinput I/F 84, the user gives an instruction for setting a videorecording mode RMB, a video recording mode in which white light imagesWIA sequentially outputted from the processor 4 in the fluorescenceobservation mode to be recorded to the video recording apparatus 6during a predetermined period.

The video recording controlling portion 85 generates video recordingcontrol information for causing recording of the white light images WIAto be continued until a time point after a predetermined period afterthe end of the fluorescence occurrence period PFP, and outputs the videorecording control information to the video recording managing portion86, based on the analysis result information outputted from the imageanalyzing portion 46, the observation mode information outputted fromthe controlling portion 49, and the instructions from recorded imagesetting switch and the video recording mode setting switch of the inputI/F 84. Further, the video recording controlling portion 85 generatesvideo recording control information for, while causing fluorescenceimages FIA to be recorded to the image recording portion 83 during thefluorescence occurrence period PFP, causing the fluorescence images FIAnot to be recorded to the image recording portion 83 during thefluorescence non-occurrence period PFN, and outputs the video recordingcontrol information to the video recording managing portion 86, based onthe analysis result information outputted from the image analyzingportion 46, the observation mode information outputted from thecontrolling portion 49 and the instruction from the recorded imagesetting switch of the input I/F 84.

The video recording managing portion 86 performs control for setting anoutput destination of the white light images WIA to the image recordingportion 83, to the image inputting portion 81 based on the videorecording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the white light images WIA to theimage recording portion 83 to be performed during thebefore-start-of-fluorescence-occurrence period PFNA, the fluorescenceoccurrence period PFP and an after-end-of-fluorescence-occurrence periodPFND corresponding to a predetermined period with the end of thefluorescence occurrence period PFP as a start point, during theafter-end-of-fluorescence-occurrence period PFNB, to the image inputtingportion 81 based on the video recording control information outputtedfrom the video recording controlling portion 85. Further, the videorecording managing portion 86 performs control for causing output of thewhite light images WIA to the image recording portion 83 to be stoppedat an end of the after-end-of-fluorescence-occurrence period PFND, tothe image inputting portion 81 based on the video recording controlinformation outputted from the video recording controlling portion 85.

The video recording managing portion 86 performs control for setting anoutput destination of the fluorescence images FIA to the image recordingportion 83, to the image inputting portion 81 based on the videorecording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the fluorescence images FIA tothe image recording portion 83 to be performed during the fluorescenceoccurrence period PFP, to the image inputting portion 81 based on thevideo recording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the fluorescence images FIA tothe image recording portion 83 to be stopped during the fluorescencenon-occurrence period PFN, to the image inputting portion 81 based onthe video recording control information outputted from the videorecording controlling portion 85.

According to the operation as described above, when the video recordingmode of the video recording apparatus 6 is set to the video recordingmode RMB, a movie WMB corresponding to a plurality of white light imagesWIA sequentially inputted to the image inputting portion 81 during thebefore-start-of-fluorescence-occurrence period PFNA, the fluorescenceoccurrence period PFP and the after-end-of-fluorescence-occurrenceperiod PFND is recorded to the image recording portion 83, for example,as shown in FIG. 5. Further, according to the operation as describedabove, when the video recording mode of the video recording apparatus 6is set to the video recording mode RMB, a movie FMB corresponding to aplurality of fluorescence images FIA sequentially inputted to the imageinputting portion 81 in the fluorescence occurrence period PFP isrecorded to the image recording portion 83, for example, as shown inFIG. 5. FIG. 5 is a diagram for illustrating an example of the recordingstate of images in the video recording apparatus according to theembodiment.

In other words, when the video recording mode of the video recordingapparatus 6 is set to the video recording mode RMB, the white lightimages WIA sequentially inputted to the video recording apparatus 6during the before-start-of-fluorescence-occurrence period PFNA, thefluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFND are recorded as themovie WMB, and the fluorescence images FIA inputted to the videorecording apparatus 6 during the fluorescence occurrence period PFP arerecorded as the movie FMB. Further, when the video recording mode of thevideo recording apparatus 6 is set to the video recording mode RMB,control for causing the white light images WIA to be recorded to theimage recording portion 83 is performed by the video recording managingportion 86 during the before-start-of-fluorescence-occurrence periodPFNA, the fluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFND. Further, when thevideo recording mode of the video recording apparatus 6 is set to thevideo recording mode RMB, control for causing the fluorescence imagesFIA not to be recorded to the image recording portion 83 is performed bythe video recording managing portion 86 during the fluorescencenon-occurrence period PFN. Further, when the video recording mode of thevideo recording apparatus 6 is set to the video recording mode RMB,control for causing the fluorescence images FIA to be recorded to theimage recording portion 83 is performed by the video recording managingportion 86 during the fluorescence occurrence period PFP.

For example, by operating the video recording mode setting switch of theinput I/F 84, the user gives an instruction for setting a videorecording mode RMC, a video recording mode in which white light imagesWIA sequentially outputted from the processor 4 in the fluorescenceobservation mode to be recorded to the video recording apparatus 6 onlywithin a predetermined period.

The video recording controlling portion 85 generates video recordingcontrol information for causing recording of the white light images WIAto be performed from a time point before a predetermined period beforethe start of the fluorescence occurrence period PFP to a time pointafter a predetermined period after the end of the fluorescenceoccurrence period PFP, and outputs the video recording controlinformation to the video recording managing portion 86, based on theanalysis result information outputted from the image analyzing portion46, the observation mode information outputted from the controllingportion 49 and the instructions of the recorded image setting switch andthe video recording mode setting switch of the input I/F 84. Further,the video recording controlling portion 85 generates video recordingcontrol information for, while causing fluorescence images FIA to berecorded to the image recording portion 83 during the fluorescenceoccurrence period PFP, causing the fluorescence images FIA not to berecorded to the image recording portion 83 during the fluorescencenon-occurrence period PFN, and outputs the video recording controlinformation to the video recording managing portion 86, based on theanalysis result information outputted from the image analyzing portion46, the observation mode information outputted from the controllingportion 49 and the instruction from the recorded image setting switch ofthe input I/F 84.

The video recording managing portion 86 performs control for setting anoutput destination of the white light images WIA to the image holdingportion 82 during the before-start-of-fluorescence-occurrence periodPFNA, to the image inputting portion 81 based on the video recordingcontrol information outputted from the video recording controllingportion 85. In other words, the video recording managing portion 86performs control for causing a predetermined number of white lightimages WIA to be held in the image holding portion 82 during thebefore-start-of-fluorescence-occurrence period PFNA, based on the videorecording control information outputted from the video recordingcontrolling portion 85. Then, in response to such control of the videorecording managing portion 86, N (1≤N) white light images WIA includingthe newest white light image WIA acquired during thebefore-start-of-fluorescence-occurrence period PFNA are held in theimage holding portion 82.

When detecting that the before-start-of-fluorescence-occurrence periodPFNA transitions to the fluorescence occurrence period PFP, the videorecording managing portion 86 performs control for causing the currentlyheld N white light images WIA to be outputted to the image recordingportion 83, to the image holding portion 82, and performs control forre-setting an output destination of the white light images WIA to theimage recording portion 83, to the image inputting portion 81, based onthe video recording control information outputted from the videorecording controlling portion 85. In other words, at the start of thefluorescence occurrence period PFP, the video recording managing portion86 performs control for causing output of the white light images WIAfrom the image inputting portion 81 to the image holding portion 82 tobe stopped, control for causing the N white light images WIA held in theimage holding portion 82 to be outputted to the image recording portion83, and control for causing recording of the white light images WIAsequentially outputted from the white light image generating portion 43via the image inputting portion 81 to the image recording portion 83 tobe started, based on the video recording control information outputtedfrom the video recording controlling portion 85. Further, the videorecording managing portion 86 performs control for causing output of thewhite light images WIA to the image recording portion 83 to be performedduring the fluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFND, to the image inputtingportion 81 based on the video recording control information outputtedfrom the video recording controlling portion 85. Further, the videorecording managing portion 86 performs control for causing output of thewhite light images WIA to the image recording portion 83 to be stoppedat the end of the after-end-of-fluorescence-occurrence period PFND, tothe image inputting portion 81 based on the video recording controlinformation outputted from the video recording controlling portion 85.

The video recording managing portion 86 performs control for setting anoutput destination of the fluorescence images FIA to the image recordingportion 83, to the image inputting portion 81, based on the videorecording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the fluorescence images FIA tothe image recording portion 83 to be performed during the fluorescenceoccurrence period PFP, to the image inputting portion 81 based on thevideo recording control information outputted from the video recordingcontrolling portion 85. Further, the video recording managing portion 86performs control for causing output of the fluorescence images FIA tothe image recording portion 83 to be stopped during the fluorescencenon-occurrence period PFN, to the image inputting portion 81 based onthe video recording control information outputted from the videorecording controlling portion 85.

According to the operation as described above, when the video recordingmode of the video recording apparatus 6 is set to the video recordingmode RMC, a movie WMC corresponding to a plurality of white light imagesWIA sequentially inputted to the image inputting portion 81 during abefore-start-of-fluorescence-occurrence period PFNC corresponding to apredetermined period required to acquire N white light images WIA duringthe before-start-of-fluorescence-occurrence period PFNA, thefluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFND is recorded to theimage recording portion 83, for example, as shown in FIG. 6. Further,according to the operation as described above, when the video recordingmode of the video recording apparatus 6 is set to the video recordingmode RMC, a movie FMC corresponding to a plurality of fluorescenceimages FIA sequentially inputted to the image inputting portion 81 inthe fluorescence occurrence period PFP is recorded to the imagerecording portion 83, for example, as shown in FIG. 6. FIG. 6 is adiagram for illustrating an example of the recording state of images inthe video recording apparatus according to the embodiment.

In other words, when the video recording mode of the video recordingapparatus 6 is set to the video recording mode RMC, the white lightimages WIA sequentially inputted to the video recording apparatus 6during the before-start-of-fluorescence-occurrence period PFNC, thefluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFND are recorded as themovie WMC, and the fluorescence images FIA inputted to the videorecording apparatus 6 during the fluorescence occurrence period PFP arerecorded as the movie FMC. Further, when the video recording mode of thevideo recording apparatus 6 is set to the video recording mode RMC,control for causing the white light images WIA to be recorded to theimage recording portion 83 is performed by the video recording managingportion 86 during the before-start-of-fluorescence-occurrence periodPFNC, the fluorescence occurrence period PFP and theafter-end-of-fluorescence-occurrence period PFND. Further, when thevideo recording mode of the video recording apparatus 6 is set to thevideo recording mode RMC, control for causing the fluorescence imagesFIA not to be recorded to the image recording portion 83 is performed bythe video recording managing portion 86 during the fluorescencenon-occurrence period PFN. Further, when the video recording mode of thevideo recording apparatus 6 is set to the video recording mode RMC,control for causing the fluorescence images FIA to be recorded to theimage recording portion 83 is performed by the video recording managingportion 86 during the fluorescence occurrence period PFP.

As described above, the video recording managing portion 86 estimates aperiod during which an analysis result that a fluorescence occurrencearea is not included is obtained by the process of the image analyzingportion 46, as the fluorescence non-occurrence period PFN to performcontrol, based on the video recording control information outputted fromthe video recording controlling portion 85. Further, the video recordingmanaging portion 86 estimates a period during which an analysis resultthat a fluorescence occurrence area is included is obtained by theprocess of the image analyzing portion 46, as the fluorescenceoccurrence period PFP to perform control, based on the video recordingcontrol information outputted from the video recording controllingportion 85. Further, as described above, the video recording managingportion 86 performs control for causing the white light images WIA andthe fluorescence images FIA to be recorded to the image recordingportion 83, during the fluorescence occurrence period PFP. Further, asdescribed above, when the video recording mode of the video recordingapparatus 6 is set to the video recording mode RMC, the video recordingmanaging portion 86 performs control for causing the white light imagesWIA corresponding to the predetermined period before the start of thefluorescence occurrence period PFP during the fluorescencenon-occurrence period PFN to be recorded to the image recording portion83.

In the present embodiment, for example, the image recording portion 83may be such that, in response to control of the video recording managingportion 86, performs an operation for setting an image quality (aresolution) of white light images WIA inputted to the image inputtingportion 81 during the fluorescence non-occurrence period PFN to arelatively low image quality (a low resolution) to record the whitelight images WIA and performs an operation for setting an image quality(a resolution) of white light images WIA inputted to the image inputtingportion 81 during the fluorescence occurrence period PFP to a relativelyhigh quality (a high resolution) to record the white light images WIA.

As described above, according to the present embodiment, fluorescenceimages FIA acquired during a period during which fluorescence FLA isinvisible and a period during which visibility of the fluorescence FLAis low are not video-recorded, and fluorescence images FIA acquiredduring a period during which the visibility of the fluorescence FLA ishigh are video-recorded. Therefore, according to the present embodiment,it is possible to acquire, for example, video-recorded data with aminimized data size so that only fluorescence images FIA thought to berequired for work such as diagnosis are included, and, as a result, itis possible to efficiently video-record the fluorescence images FIAacquired in the fluorescence observation mode.

Further, as described above, according to the present embodiment, whenthe video recording mode of the video recording apparatus 6 is set tothe video recording mode RMB, white light images WIA (superposed imagesSIA) acquired during a period from a time point before a state in whichfluorescence FLA is visible starts to a time point immediately after astate in which fluorescence FLA is completely invisible starts arevideo-recorded, and white light images WIA (superposed images SIA)acquired after the period are not video-recorded. Therefore, accordingto the present embodiment, when the video recording mode of the videorecording apparatus 6 is set to the video recording mode RMB, it ispossible to acquire, for example, video-recorded data with a compactdata size so that white light images WIA (superposed images SIA) thoughtto be required for work such as diagnosis are included, and, as aresult, it is possible to efficiently video-record white light imagesWIA (superposed images SIA) acquired in the fluorescence observationmode.

Further, as described above, according to the present embodiment, whenthe video recording mode of the video recording apparatus 6 is set tothe video recording mode RMC, white light images WIA (superposed imagesSIA) acquired during a period from a time point immediately before thestate in which fluorescence FLA is visible starts to a time pointimmediately after the state in which fluorescence FLA is completelyinvisible starts are video-recorded, and white light images WIA(superposed images SIA) acquired outside the period are notvideo-recorded. Therefore, according to the present embodiment, when thevideo recording mode of the video recording apparatus 6 is set to thevideo recording mode RMC, it is possible to acquire, for example,video-recorded data with a minimized data size so that only white lightimages WIA (superposed images SIA) thought to be required for work suchas diagnosis, and, as a result, it is possible to efficientlyvideo-record white light images WIA (superposed images SIA) acquired inthe fluorescence observation mode.

Note that, according to the present embodiment, for example, the imageanalyzing portion 46 may perform a process for, based on a feature valuerelated to a color tone of superposed images SIA outputted from thesuperposed image generating portion 45, analyzing whether anfluorescence occurrence area is included in the superposed images SIA ornot, in the fluorescence observation mode, and output analysis resultinformation showing an analysis result obtained by the process to thevideo recording apparatus 6.

Further, according to the present embodiment, for example, the imageanalyzing portion 46 may perform a process for comparing a white lightimage WIA outputted from the white light image generating portion 43 anda superposed image SIA outputted from the superposed image generatingportion 45 and output analysis result information showing an obtainedanalysis result to the video recording apparatus 6, in the fluorescenceobservation mode.

For example, if analysis result information showing an analysis resultthat the white light image WIA outputted from the white light imagegenerating portion 43 corresponds to the superposed image SIA outputtedfrom the superposed image generating portion 45 is outputted from theimage analyzing portion 46, an operation that is substantially the sameas the operation in the case where an analysis result showing that anfluorescence occurrence area is not included in a fluorescence image FIAoutputted from the fluorescence image generating portion 44 is obtainedis performed in the video recording apparatus 6. Further, for example,if analysis result information showing an analysis result that the whitelight image WIA outputted from the white light image generating portion43 does not correspond to the superposed image SIA outputted from thesuperposed image generating portion 45 is outputted from the imageanalyzing portion 46, an operation that is substantially the same as theoperation in the case where an analysis result showing that anfluorescence occurrence area is included in fluorescence images FIAoutputted from the fluorescence image generating portion 44 is obtainedis performed in the video recording apparatus 6.

Further, according to the present embodiment, for example, the imageanalyzing portion 46 may be configured having a function as a distancecalculating portion configured to perform a process for calculating anobservation distance VD corresponding to a distance between the distalend portion of the insertion portion 21 of the endoscope 2 and an objectto which the excitation light EXA is radiated, based on white lightimages WIA outputted from the white light image generating portion 43,in the fluorescence observation mode. In such a case, for example, theimage analyzing portion 46 can output analysis result informationshowing an analysis result obtained by comparing the observationdistance VD and a predetermined value THW, to the video recordingapparatus 6. Further, in the case as described above, for example, thevideo recording managing portion 86 can estimate a period during whichan analysis result that the observation distance VD is equal to or abovea predetermined threshold THW as the fluorescence non-occurrence periodPFN to perform control and estimate a period during which an analysisresult that the observation distance VD is below the predeterminedthreshold THW as the fluorescence occurrence period PFP to performcontrol, based on the video recording control information outputted fromthe video recording controlling portion 85.

According to the present embodiment, for example, when an instructionfor causing predetermined additional information to be recorded togetherat the time of video recording is given on the input I/F 84, videorecording control information corresponding to the instruction may beoutputted from the video recording controlling portion 85, and controlcorresponding to the video recording control information may beperformed by the video recording managing portion 86. A specific exampleof an operation performed in such a case will be described below.

For example, when an instruction for causing a time stamp to be recordedtogether at the time of video recording is given on the input I/F 84,the video recording managing portion 86 may perform control for causingcharacter information showing a date and time when a recording targetimage RIA (corresponding to at least one image among the white lightimages WIA, the fluorescence images FIA and the superposed images SIA),which is an image set as a recording target, was inputted to be added tothe recording target image RIA to perform recording, to the imagerecording portion 83, according to the video recording controlinformation outputted from the video recording controlling portion 85.According to such control of the video recording managing portion 86, anoperation for adding character information MJA showing the date and timewhen the recording target image RIA was inputted, at a lower part of therecording target RIA to perform recording is performed by the imagerecording portion 83 (see FIG. 7). FIG. 7 is a diagram for illustratingan example of additional information recorded to the video recordingapparatus according to the embodiment.

For example, when an instruction for causing metadata to be recordedtogether at the time of video recording is given on the input I/F 84,the video recording managing portion 86 may perform control for causingcharacter information including a recording start date and time and arecording end time and date of the recording target image RIA to berecorded separately from the recording target image RIA, to the imagerecording portion 83, according to the video recording controlinformation outputted from the video recording controlling portion 85.According to such control of the video recording managing portion 86,for example, an operation for generating and recording a text file TFA,which has pieces of character information MJB and MJC as shown in FIG. 8and is data separate from the recording target image RIA is performed bythe image recording portion 83. FIG. 8 is a diagram for illustrating anexample of the additional information recorded to the video recordingapparatus according to the embodiment.

The character information MJB in FIG. 8 includes, for example,information about a patient inputted by the user operating the input I/F84 before performing observation by the endoscope 2. Further, thecharacter information MJC in FIG. 8 includes, for example, a recordingstart time and date and a recording end time and date in a case whererecording target images in the white observation mode is set to whitelight images WIA, and a recording start time and date and a recordingend time and date in a case where recording target images in thefluorescence observation mode are set to white light images WIA andfluorescence images FIA. Note that when the video recording mode RMAdescribed above is given as an example, “2017/10/25 09:00:00” includedin the character information MJC in FIG. 8 corresponds to the recordingstart time and date of white light images WIA; “2017/10/25 11:00:00”included in the character information MJC corresponds to the recordingend time and date of the white light images WIA; “2017/10/25 10:00:01”included in the character information MJC corresponds to the recordingstart time and date of white light images WIA and fluorescence imagesFIA; and “2017/10/25 10:10:00” included in the character information MJCcorresponds to the recording end time and date of the white light imagesWIA and the fluorescence images FIA. Further, when the video recordingmode RMA described above is given as an example, “2017/10/25 10:00:00”included in the character information MJC in FIG. 8 corresponds to atime and date of an end of the before-start-of-fluorescence-occurrenceperiod PFNA, and “2017/10/25 10:10:01” included in the characterinformation MJC corresponds to a time and date of a start of theafter-end-of-fluorescence-occurrence period PFNB.

For example, when an instruction for causing title information to berecorded together at the time of video recording is given on the inputOF 84, the video recording managing portion 86 may perform control forcausing a title image, which is an image including character informationfor informing that the fluorescence occurrence period PFP has beenstarted, to be recorded as additional information and causingfluorescence images FIA to be recorded immediately after the titleimage, to the image recording portion 83, according to video recordingcontrol information outputted from the video recording controllingportion 85. According to such control of the video recording managingportion 86, for example, an operation for generating one or more titleimages TIA including the pieces of character information MJD and MJE asshown in FIG. 9 and starting recording of fluorescence images FIA afterinserting the generated title images TIA into a forefront part of themovie FMA, FMB or FMC described above is performed by the imagerecording portion 83. FIG. 9 is a diagram for illustrating an example ofthe additional information recorded to the video recording apparatusaccording to the embodiment.

The character information MJD in FIG. 9 includes, for example,information about the patient inputted by the user operating the inputI/F 84 before performing observation by the endoscope 2. Further,character information MJE in FIG. 9 includes, for example, informationshowing a time and date of the start of the fluorescence occurrenceperiod PFP.

In the present embodiment, instead of the operation of inserting thetitle images TIA described above, for example, such an operation ofsuperposing visual information such as an icon capable of informing thatthe fluorescence occurrence period PFP has been started on one or morefluorescence images FIA belonging to the forefront part of the movieFMA, FMB or FMC may be performed by the image recording portion 83.

The present invention is not limited to the embodiment described above,but various changes and applications are, of course, possible within arange not departing from the spirit of the invention.

What is claimed is:
 1. An endoscope system comprising: a processor; alight source configured to be capable of emitting excitation light forcausing a fluorescent agent administered to a subject to be excited andillumination light for illuminating an inside of the subject; and animage pickup device configured to pick up images of each of fluorescencethat occurs in response to radiation of the excitation light to anobject existing inside the subject to whom the fluorescent agent hasbeen administered, and reflected light that occurs in response toradiation of the illumination light to the object; wherein the processorgenerates and sequentially outputs reflected light images which areimages corresponding to the reflected light picked up by the imagepickup device; generates and sequentially outputs fluorescence imageswhich are images corresponding to the fluorescence light picked up bythe image pickup device; records each of the sequentially outputtedreflected light images and the sequentially outputted fluorescenceimages to a first storage medium; performs control for causing thereflected light images and the fluorescence images to be recorded to thefirst storage medium in a fluorescence occurrence period, which is aperiod during which the fluorescence occurs, performs control forcausing the fluorescence images not to be recorded to the first storagemedium during a fluorescence non-occurrence period, which is a periodduring which the fluorescence does not occur, and performs control forcausing reflected light images corresponding to a predetermined periodbefore start of the fluorescence occurrence period during thefluorescence non-occurrence period, among the reflected light images, tobe recorded to the first storage medium; and furthermore, performscontrol for causing the reflected light images to be recorded to thefirst storage medium during an after-end-of-fluorescence-occurrenceperiod corresponding to a predetermined period with an end of thefluorescence occurrence period as a start point, and performs controlfor causing the reflected light images not to be recorded to the firststorage medium during the fluorescence non-occurrence period after anend of the after-end-of-fluorescence-occurrence period.
 2. An endoscopesystem comprising: a processor; a light source configured to be capableof emitting excitation light for causing a fluorescent agentadministered to a subject to be excited and illumination light forilluminating an inside of the subject; and an image pickup deviceconfigured to pick up images of each of fluorescence that occurs inresponse to radiation of the excitation light to an object existinginside the subject to whom the fluorescent agent has been administered,and reflected light that occurs in response to radiation of theillumination light to the object; wherein the processor generates andsequentially outputs reflected light images which are imagescorresponding to the reflected light picked up by the image pickupdevice; generates and sequentially outputs fluorescence images which areimages corresponding to the fluorescence light picked up by the imagepickup device; records each of the sequentially outputted reflectedlight images and the sequentially outputted fluorescence images to afirst storage medium; performs control for causing the reflected lightimages and the fluorescence images to be recorded to the first storagemedium in a fluorescence occurrence period, which is a period duringwhich the fluorescence occurs, performs control for causing thefluorescence images not to be recorded to the first storage medium in afluorescence non-occurrence period, which is a period during which thefluorescence does not occur, and performs control for causing thereflected light images corresponding to a predetermined period beforestart of the fluorescence occurrence period during the fluorescencenon-occurrence period, among the reflected light images, to be recordedto the first storage medium; furthermore, holds a predetermined numberof the sequentially outputted reflected light images in a second storagemedium; and performs control for causing the predetermined number of thereflected light images to be held in the second storage medium during abefore-start-of-fluorescence-occurrence period corresponding to a periodbefore start of occurrence of the fluorescence during the fluorescencenon-occurrence period, and performs control for causing output of thereflected light images to the second storage medium to be stopped,control for causing the predetermined number of the reflected lightimages held in the second storage medium to be outputted to the firststorage medium and control for causing recording of the sequentiallyoutputted reflected light images to the first storage medium to bestarted, at the start of the fluorescence occurrence period.
 3. Theendoscope system according to claim 1, wherein the processor performs aprocess for analyzing whether a fluorescence occurrence area is includedin the fluorescence images, based on a feature value related tobrightness of the fluorescence images; and estimates a period duringwhich an analysis result that the fluorescence occurrence area is notincluded, as the fluorescence non-occurrence period, to perform control,and estimates a period during which an analysis result that thefluorescence occurrence area is included, as the fluorescence occurrenceperiod, to perform control.
 4. The endoscope system according to claim1, wherein the processor performs a process for calculating anobservation distance corresponding to a distance between a distal endportion of an insertion portion of an endoscope provided with the imagepickup device and the object to which the excitation light is radiated,based on the reflected light images; and estimates a period during whichan analysis result that the observation distance is equal to or above apredetermined threshold, as the fluorescence non-occurrence period, toperform control, and estimates a period during which an analysis resultthat the observation distance is below the predetermined threshold, asthe fluorescence occurrence period, to perform control.
 5. The endoscopesystem according to claim 1, wherein the processor generates andsequentially outputs superposed images obtained by superposing thereflected light images and the fluorescence images, respectively; andperforms control for causing the superposed images to be recorded to thefirst storage medium instead of the reflected light images and performscontrol for causing superposed images corresponding to the predeterminedperiod, among the superposed images, to be recorded to the first storagemedium instead of the reflected light images, during the fluorescenceoccurrence period.
 6. The endoscope system according to claim 1, whereinthe processor also performs, at time of performing control for causing arecording target image corresponding to at least any one of thereflected light images and the fluorescence images to be recorded to thefirst storage medium, control for adding information showing a time anddate when the recording target image is inputted to the first storagemedium to the recording target image to cause the recording target imageto be recorded.
 7. The endoscope system according to claim 1, whereinthe processor also performs, at time of performing control for causing arecording target image corresponding to at least any one of thereflected light images and the fluorescence images to be recorded to thefirst storage medium, control for causing information including arecording start time and date and a recording end time and date of therecording target image to be recorded separately from the recordingtarget image.
 8. The endoscope system according to claim 1, wherein theprocessor performs control for causing a title image includinginformation for informing that the fluorescence occurrence period hasbeen started to be recorded and causing the fluorescence images to berecorded immediately after the title image.
 9. An endoscope processorcomprising a processor configured to process a signal about fluorescencegenerated by causing a fluorescent agent administered to a subject to beexcited and a signal about reflected light that occurs in response toillumination to an inside of the subject; wherein the processorgenerates reflected light images from the signal about the reflectedlight and sequentially outputs the reflected light images; generatesfluorescence images from the signal about the fluorescence andsequentially outputs the fluorescence light images; performs control forcausing the reflected light images and the fluorescence images to berecorded to an external recording apparatus in a fluorescence occurrenceperiod, which is a period during which the fluorescence occurs, performscontrol for causing the fluorescence images not to be recorded to theexternal recording apparatus in a fluorescence non-occurrence period,which is a period during which the fluorescence does not occur, andperforms control for causing reflected light images corresponding to apredetermined period before start of the fluorescence occurrence periodduring the fluorescence non-occurrence period, among the reflected lightimages, to be recorded to the external recording apparatus; andfurthermore, performs control for causing the reflected light images tobe recorded to the external recording apparatus during anafter-end-of-fluorescence-occurrence period corresponding to apredetermined period with an end of the fluorescence occurrence periodas a start point, and performs control for causing the reflected lightimages not to be recorded to the external recording apparatus during thefluorescence non-occurrence period after an end of theafter-end-of-fluorescence-occurrence period.